i) Field of the Invention
The present invention relates to an optical disk recording/reproducing apparatus constituted for recording of a signal on a disk using a laser emitted from an optical pickup and for reading of a signal recorded on the disk.
ii) Description of Related Art
Disk players having an optical pickup for reading signals recorded on a disk have become common items, and in recent years optical disk recording/reproducing apparatuses having a constitution providing them with, in addition to signal reproduction capability, a capability of recording a signal on a disk using laser light emitted from the optical pickup have also become commercially available.
Such optical disk recording/reproducing apparatuses use a laser to form a pit on a recording disk. However, in such devices, when laser output is not optimum, the formed pit will be too large or too small. Therefore, a trial writing region is disposed along the inner periphery of disks for use with such optical disk recording/reproducing apparatuses. In such systems, a signal is first recorded in the trial writing region and then retrieved. The reproduced signal is analyzed, and this information is used to set the laser output for recording. Such a technique is disclosed in, for example, Japanese Patent Laid-Open No. Hei 6-76288.
For an operation for recording a signal into a disk, a linear speed is not a defined constant. A technique has been developed in which the recording operation can be performed at constant linear speeds such as four, six, eight, ten, and twelve times the defined linear speed. When the recording operation is performed at a constant linear speed, accurate rotation speed control operation by a spindle motor for rotating/driving the disk must be maintained. As a result, it is difficult to perform recording operations at higher linear speeds.
As a technique for addressing this problem, a technique has been developed in which the rotation speed control operation of the disk during the recording operation is performed at a constant angular speed rather than at a constant linear speed. However, because the linear speed of a disk rotated at a constant angular speed varies widely between the inner and outer peripheries, a difficulty remains in that it is difficult to set the laser output suitable for the recording operation at each speed.